YSI pH and pH/ORP sensors have been carefully designed to perform under all ionic strength conditions, from seawater with a conductivity of 53,000 μS/cm, to "average" freshwater lakes and rivers with conductivities of 200 to 1500 μS/cm, to pure mountain streams with conductivities as low as 15 μS/cm, which has historically been the most difficult medium with respect to accuracy, quick response to pH changes, and minimal flow dependence.
ORP is determined by measuring the potential of a chemically-inert (platinum) electrode which is immersed in the solution. The sensing electrode potential is read relative to the reference electrode of the pH probe and the value is presented in millivolts.
6569 Hemispherical pH/ORP Sensor:
The YSI 6569 Hemisphere pH/ORP Sensor is a longer-length probe with hemispherical glass bulb. This extended length allows it to be wiped by 6600V2-4 sonde brush, and it's hemispherical shape protects most of the bulb. 6579 pH Hemispherical Probe also available.
- Greater length allows it to be wiped by 6600V2-4 sonde brush.
- Hemispherical shape protects most of the bulb.
- Unguarded. May occasionally produce jumpy readings.
Sensor is available for use on the following sonde:
- 6600 V2-4 with wiper/brush only
Range: 0 to 14 units
Resolution: 0.01 unit
Accuracy: ±0.2 unit
U.S. EPA ETV